Self-energizing and self-aligning double-acting brake assembly

ABSTRACT

A double-acting brake assembly comprising a drum mounted on a rotary shaft, a brake band with looped ends surrounding the drum, and actuator means to displace ends of the band toward one another, is provided with a mounting bracket having spaced reaction surfaces which cooperate with the ends of the band to permit the band to wrap onto the drum for braking the drum when rotating in either the clockwise or counterclockwise directions. The reaction surfaces extend widthwise of the band adjacent the periphery of the drum, and a pair of guide surfaces extend alongside the ends of the band for aligning the band axially of the drum. In one embodiment, the bracket has an L-shaped crosssection with a flange overlying the drum and the reaction and guide surfaces are provided by the edges of an aperture in the flange. Other forms of brackets, including a bracket combined with a dust cover, are also disclosed. A preferred form of actuator includes a flexible sheath and cable assembly having one end connected to an operating lever and the other end connected to the ends of the band. The actuator draws the looped ends of the band together to engage the band with the drum, but allows lost motion between the end loops and the reaction surfaces of the mounting bracket. The end loops are free to move against either reaction surface, so that no matter which direction the drum is rotating, it will be the end loop at the leading end of the band which engages a reaction surface, and the trailing end of the band will in every case be free to wrap about the drum to provide a servo or self-energizing braking action. This will provide self-energizing braking on both forward and reverse rotation of the drum.

United States Patent [191 Boaz [ Aug. 13, 1974 SELF-ENERGIZING ANDSELF-ALIGNING DOUBLE-ACTING BRAKE ASSEMBLY [76] Inventor: Edward G.Boaz, PO. Box 60,

Ottsville, Pa. 18942 22 Filed: Feb.22, 1973 21 Appl.No.:334,564

[52] US. CL... 188/77 R, 188/2 D, 188/26 [51] Int. Cl. Fl6d 51/04 [58]Field Of Search 188/26, 77, 2 D; 192/80 [56] References Cited UNITEDSTATES PATENTS 1,947,823 2/1934 Brey 188/77 R 2,048,420 7/1936 Babel188/77 R 3,240,293 3/1966 Ferguson'et al. 188/2 D 3,495,690 2/1970 Otten192/80 Primary Examiner-Trygve M. Blix Assistant Examiner-Sherman D.Basinger Attorney, Agent, or Firm-Howson & Howson 5 7 ABSTRACT Adouble-acting brake assembly comprising a drum mounted on a rotaryshaft, a brake band with looped ends surrounding the drum, and actuatormeans to displace ends of the band toward one another, is .provided witha mounting bracket having spaced reaction surfaces which cooperate withthe ends of the band to permit the band to wrap onto the drum forbraking the drum when rotating in either the clockwise orcounterclockwise directions. The reaction surfaces extend widthwise ofthe band adjacent the periphery of the drum, and a pair of guidesurfaces extend alongside the ends of the band for aligning the bandaxially of the drum. In one embodiment, the bracket has an L- shapedcross-section with a flange overlying the drum and the reaction andguide surfaces are provided by the edges of an aperture in the flange.Other forms of brackets, including a bracket combined with a dust cover,are also disclosed. A preferred form of actuator includes a flexiblesheath and cable assembly having one end connected to an operating leverand the other end connected to the ends of the band. The actuator drawsthe looped ends of the band together to engage the band with the drum,but allows lost motion between the end loops and the reaction surfacesof the mounting bracket. The end loops are free to move against eitherreaction surface, so that no matter which direction the drum isrotating, it will be the end loop at the leading end-of the band whichengages a reaction surface, and the trailing end of the band will inevery case be free to wrap about the drum to provide a servo orself-energizing braking action. This will provide self-energizingbraking on both forward and reverse rotation of the drum.

13 Claims, 13 Drawing Figures SELF-ENERGIZING AND SELF-ALIGNINGDOUBLE-ACTING BRAKE ASSEMBLY The present invention relates to brakes,and more particularly, the present invention relates to doubleactingband-type brake assemblies.

Some recreational vehicles (such as all-terrain vehicles) and utilityvehicles (such asv ridingmowers and light tractors) presently on themarket are provided with single-acting braking systems. Such systemsusually include a brake drum, a band surrounding the drumand having oneend fixed to the frame of the vehicle, and actuator means to displacethe other or free end of the band toward the fixed end. As long as theperiphery of the drum is rotating in a direction which carries itssurrounded surface, from the fixed end toward the free end of the band,the band wraps onto the drum when actuated and the band isself-energizing. However, when the drum rotates in the other direction,the band tends to unwrap from the drum, resulting in only a minimalbraking action. This type of brake is normally employed to stop avehicle moving in a forward direction; it is not capable of providing asatisfactory braking action for stopping the same-vehicle when travelingin the reverse direction, for example to prevent the vehicle from movingbackward when stopped on an incline. As a result, vehicles havingsingle-acting braking systems are not as safe to use as desired.

Double-acting braking systems are known. Examples of such brakingsystems are disclosed in U.S. Pat. Nos.: 2,304,646; 1,673,211; and2,703,155. Although these patented brake assemblies may be satisfactoryfor their intended purposes, none is of such simple construction as tobe capable of being manufactured inexpensively. In addition, none iscapable of being used in conjunction with a conventional brake band in amanner which permits single acting systems to be converted in the fieldinto double-acting systems.

In US. Pat. No. 1,673,211 there is disclosed a double-acting brakeassembly which comprises a band surrounding a brake drum and having endsdisplaceable toward one another by means of an actuator assembly forcausing the band to engage the drum to effect a braking action. The endshave elongated slots for receiving pins which provide stops againstwhich the ends engage, depending on the direction of rotation of thedrum when the brake is activated. The pins are mounted to move toward oraway from one another to permit the band to be adjusted relative to thedrum. In addition, there is provided means for supporting the band at alocation diametrically opposed to the ends so that the band is normallyspaced from the drum when the brake is de-activated. Although this brakemay operate satisfactorily, the activating mechanism is complex andexpensive to manufacture. and has a number of moving parts which aresubject to wear, particularly in severe service conditions where foreignmatter is likely to permeate the assembly. Moreover, since theactivating mechanism is relatively bulky, it may not be used in vehicleswhere spatial limitations require compact brake assemblies. This brakepossesses a further limitation in its inability to be used to convert anexisting single-acting system into a double-acting system withoutrequiring substantial modifications.

With the foregoing in mind, it is a primary object of the presentinvention to provide a novel double-acting 2 brake assembly which isrelatively inexpensive to manufacture and use.

It is another object of the present invention to provide a uniquedouble-acting brake assembly which possesses both self-energizing andself-aligning capabilities.

As a further object, the present invention provides an improveddouble-acting brake assembly which possesses a minimum of moving parts.

It is still another object of the present invention to provide adouble-acting brake assembly with an actuating mechanism which isrelatively compact to permit the assembly to be installed in vehicleshaving spatial limitations.

As a still further object, the present invention provides adouble-acting brake assembly which is resistant to wear even whenutilized under severe service conditions.

It is an important object of the present invention to provide a durable,one-piece bracket which is capable of being employed in conjunction witha brake band and a sheathed cable to provide a double-acting brake.

As an additional object, the present invention provides a bracket whichis capable of being installed in vehicles having single-acting band-typebraking systems to convert the single-acting systems into doubleactingsystems with a minimum of labor and/or modifications to the vehicle.

More specifically, in the present invention a brake assembly comprisinga brake drum surrounded by a band having looped ends spaced from oneanother and an actuator connected to the ends to draw them together isprovided with a mounting bracket having a pair of spaced reactionsurfaces which embrace the looped ends of the band for limiting rotationof the band relative to the drum when the ends are drawn together toeffect a braking action. A pair of guide surfaces extend in spacedparallel relation alongside of the ends of the band and between thereaction surfaces for aligning the band axially of the drum. A preferredactuator includes a flexible cable assembly having a cable elementtelescopically mounted inside a slack sheath. One end of the cableelement is connected to an operating lever, and the other end of thecable element passes slidably through a pin in one looped end of theband and is fixed in a pin in the other looped end of the band. Thecable sheath is arranged to abut the first pin, so that as the cable isdrawn into the sheath by the operator, the two band ends will be forcedtoward each other to draw the band into braking engagement with thedrum. The cable and sheath are free to move relative to the mountingbracket, and thus. permit lost motion between the drawn-together bandend-loops and the bracket reaction surfaces. This leaves the end loopsfree to move against either reaction surface as the direction of drumrotation dictates. Hence, regardless of the direction of drum rotationit will always be the loop at the leading end of the band (relative tothe direction of drum rotation) which will engage the reaction surface,and the trailing end of the band will always be free to wrap onto thedrum with a servo or self-energizing action. Accordingly, the brakeassembly is double acting and a self-energizing braking action isprovided so that the brake assembly may be employed in vehicles whereboth forward and reverse braking actions are desired. In one embodiment,the bracket has an L-shaped 3 cross-section with a reaction flange, andthe reaction and guide surfaces are provided by an aperture in thereaction flange. In other embodiments, the surfaces are provided bybolts and wire forms, and by a cover enclosing the band and drum. TheL-shaped bracket is also capable of being installed in a brake assemblyin which a rigid rod is employed as an actuator.

These and other objects, features and advantages of the presentinvention should become apparent from the following description whentaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a double-acting brake assembly embodyingthe present invention;

FIG. 2 is an enlarged partly sectioned side elevational view of thebrake assembly of FIG. 1, the view illustrating the brake assembly in aninactive position with both ends of a brake band engaging reactionsurfaces provided by a bracket;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a sectional view illustrating the position of the ends'of theband relative to the reaction surfaces of the bracket when the brake isactivated and the drum is rotating in the clockwise direction, thelooped end at the right being the leading end in this situation;

FIG. 5 is a view similar to FIG. 4 but illustrating the position of theends of the band relative to the bracket when the brake is activated andthe drum is rotating in the counterclockwise direction, the looped endat the left being .the leading end in this situation;

FIGS. 6 and 8 are side elevational views of modified embodiments of thepresent invention;

FIGS. 7 and 9 are plan views'of the modified embodiments illustrated inFIGS. 6 and 8, respectively;

FIG. 10 is a side elevational view of another modified embodiment of thepresent invention wherein the brake drum and band are substantiallyenclosed by means of a cover;

FIG. 11 is a plan view of the embodiment of FIG. 10;

FIG. 12 is a side elevational view of still another modified embodimentof the present-invention wherein the mounting bracket is utilized inconjunction with a brake assembly actuated by a rigid actuator rod; and

FIG. 13 is a plan view of the embodiment illustrated in FIG. 12.

Referring now to the drawings, there is illustrated in FIG. 1 adouble-acting brake assembly 10 embodying the present invention. Thebrake assembly 10 is illustrated in conjunction with a rear axle 12 of avehicle such as an allterrain vehicle having ahandle bar 11. Anoperating lever 13 is mounted on the handle bar 11, and the lever 13 isconnected through a flexible sheathed cable assembly 14 to the brakeassembly 10 to cause the brake assembly 10 to be activated when thelever 13 is depressed toward the handle bar 11. Although the assembly 10is illustrated in conjunction with a rear axle of an all-terrainvehicle, it should be apparent that it may be employed effectively inother ve-' hicles where a double-acting brake is desired. For instance,the brake assemblies of the present invention may be associated with thedrive trains of such vehicles as tractors, riding mowers, snowmobilesand the like. In place of the operating lever 13 a foot pedal may beprovided to activate the brake assembly 10.

' As best seen in FIG. 2,'the brake assembly 10 comprises a cylindricalbrake drum l5 fixedly secured to the axle or shaft 12, a brake band 16surrounding substantially the entire periphery of the drum l5, andactuator means indicated generally at 20 for causing the band 16 toengage the drum 15. In the present instance, the band 16 is ofconventional construction, comprising an inner layer of frictionmaterial 17 confronting the drum and an outer strip of steel 18 bondedto the outside of the friction material 17. The steel strip 18 has endswhich are reversely turned and fastened to form closed loops 18a and 18bwhich are spaced from one another at the top of the drum 15. As may beseen in FIG. 3, each end, such as the left and 18b, has an upwardly-openslot 18c. Brake bands of this construction are presently in service inconventional single-acting braking systems.

A braking action is effected when the actuating means 20 displaces thelooped ends 18a and 18b toward one another to cause the frictionmaterial 17 to engage the drum 15. Depending on the direction ofrotation of the drum 15, however, the ends 18a and 18b will tend torotate with the drum 14 as the friction material 17 begins to engage thedrum 15. In order to limit rotation of the band 16 relative to the drum15, the present invention provides a bracket 19 having a pair ofreaction or limit surfaces 21a and 21b engageable by the looped endsl8aand 18b respectively.

In the present instance, the vehicle has a frame member 23which'overlies and extends transversely to the rear axle l2, and thebracket 19 is fastened to the frame member 23. As best seen in FIG. 3,cross-section bracket 19 has an L-shaped corss-section with ahorizontally-disposed reaction flange 24 overlying the brake drum 15 inclosely-spaced relation therewith and a vertically-disposed mountingflange 25 secured to the frame member 23 as by bolts, welding or thelike. In the embodiment illustrated in FIGS. l-5, the reaction or limitsurfaces 21a and 21b extend widthwise of the band 16 (FIG. 3) and engagethe looped ends 18a and 18b along their entire widths so that contactstresses on the looped ends 18a and 18b as well as on the reactionsurfaces 21a and 21b are minimized for rendering the brake assembly 10resistant to wear.

In order to align the band 16 axially with the drum 15, the bracket 19has a pair of guide surfaces 26a and 26b extending in parallel relationalongside the looped ends 18a and 18b of the band 16. In the presentinstance, the guide surfaces 26a and 26b are provided by webs 27 and 28which remain after a rectangular aperture 29 (FIG. 1) is punched in thereaction flange 24. It is noted that the limit surfaces 21a and 21b areprovided by the widthwise-extending edges of the aperture 29 and theguide surfaces 26a and 26b are provided by the lengthwise-extendingedges of the aperture 29.

As best seen in FIG. 2, the limit surfaces 21a and 21b are spaced fromone another a distance which is less than the diameter of the drum 15,and as best seen in FIG. 3, the guide surfaces 26a and 26b are spacedfrom one another a distance which is slightly greater than the width ofthe band 16 as to provide a clearance. The reaction flange 24 is locatedin a plane which is disposed substantially tangential to the top of thedrum 15 and adjacent the bases of the looped ends 18a and 18b,respectively, of the band 16. Thus, the looped ends and 18b arecontained by the aperture 29 and are prevented from being displacedbeyond the reaction surfaces 2la and 21b when the band 16 engages thedrum 15. It is noted that the steel strip 18 of the band 16 possesses asufficient amount of elasticity as to bias both of the looped ends 18aand 18b against their respective reaction surfaces 21a and 21b when thebrake assembly is deactivated. As a result, the band 16 is normallyspaced a slight distance from the periphery of the drum and is therebyprevented from rubbing on the drum 15.

As noted above, when the actuator means displaces the looped ends 18aand-18b toward one another, the ends 18a and 18b tend to rotate in thedirection of rotation of the drum 15 until one or the other of themengages its associated reaction surface. The end which engages thereaction surface may be termed the leading end, and the end which wrapsonto the drum may be termed the trailing end. For instance, asillustrated in FIG. 4, the right end 18a engages the right limit surface21a when the drum 15 is rotating clockwise; hence it is the leading endand the left end 18b is the trailing end. As seen in FIG. 5, the leftend 18b engages the left limit surface 2lb when the drum 15 is rotatingcounterclockwise; hence, it is the leading end and the right end 18a isthe trailing end. When'one of the looped ends, such as the right end 18aengages its limit surface 21a, rotation of the portion of the band 16adjacent the end 18a is arrested and the remainder of the band 16 tendsto wrap onto the drum 15 as long as the band ends 18a and 18b are urgedtoward one another by the actuator 20. In wrapping, the left or trailingend 18b tends to move'rightward toward the right or leading end 18a andthe band thus has a selfenergizing action which greatly enhances thebraking effect. This progressively increases with increased actuatingpressure on the operating lever, and may increase until the band 16wraps tightly onto the drum 15. The same action occurs when the drum 15is rotating in the opposite direction; however, the left end 18b engagesits limit surface 21b and the right end 18a tends to move leftwardtoward the left end 1812 as the band 16 wraps onto the drum 15. r

In the present invention, a compact actuating mechanism is provided tourge the ends 18a and 18b of the band 16 toward one another. To thisend, the actuator mechanism is provided by means of a conventionalsheathed cable assembly 14 which has a fixed end portion 14a connectedto the operator lever 13 and which has a freely movable end portion 14bconnected to the ends 18a and 18b of the brake band 16. The cableassembly 14 comprises an outer sheath 30 which slidably encloses aninner cable 31. At the fixed end portion of the assembly, the sheath 30is fixed to a collar 13a mounted on the handle bar and the cable 31 isconnected to an eccentric anchor 13b on the operating lever 13.

As best seen in FIGS. 2 and 3, the free end 14b of the cable assembly 14is disposed substantially tangential to the drum 15 and overlies thereaction flange 24 in closely spaced relation. The cable element 31 isconnected to the left-end 18b of the band 16 by means of a pin 32 whichis carried in the looped end 18b. In the present instance, the pin 32has a transverse bore 32a in registry with the slot 180 in the left end18b of the band 16, and the cable element 31 is secured to the pin 32 bymeans of a threaded fastener or set screw 35 which is threaded into anaxially extending bore in the pin 32 and which bears against thecableelement 31 when tightened. It is noted that the cable element 31 engagesthe slot 180 to prevent the pin 32 from moving axially in the loop 18b.

The cable element 31 is secured to the right end 18a of the band 16 bymeans of a free sliding connection. In the present instance, the slidingconnection is provided by a pin 33 which is mounted in the right loop18a and a transverse bore 33a which slidably receives the cable 31. Thesheath 30 terminates in an abutment surface 30a which normally engagesthe outside of the right end 18a but which is slightly spaced therefromfor illustration purposes in FIG. 2. With this structure, depression ofthe lever 13 pulls the cable 31 into the sheath 30 to cause the bandends 18a and 18b to move toward one another until the friction material17 of the brake band 16 engages the periphery of the drum 15. The freeend 14b of the cable assembly is free to move relative to the bracket19. Accordingly, if the drum is rotating clockwise as indicated in FIG.4, the tightened band 16 tends to move in that same direction to engagethe right end-loop 18a against its associated reaction surface 21a, withthe left end-loop 18b tending to move rightward also. The band 16thereby wraps itself on the drum 15 to produce a self-energizing brakingaction. Conversely, if the drum is rotating counterclockwise asindicated in FIG. 5, the left end-loop 18b engages its associatedreaction surface 21b to initiate the braking action, and the right end18a of the band 16 tends to wrap around the drum 15 to produce aself-energizing action. Thus, in both directions of rotation, aselfenergizing action is obtained, and a double-acting braking effect isprovided with a compact and simple structure. It is noted that in orderto prevent the cable element 31 and/or its sheath 30 from binding, thepins 32 and 33 are dimensioned so as to permit them to pivot slightlyrelative to their mounting loops 18a and 18b, and if desired, a slightamount of lubricant may be provided around the pins 32 and 33 to furtherreduce any tendency for binding.

The brake assembly 10 of the present invention provides a braking actioneven as the friction material on the band wears in use. When installedinitially, the cable 31 is pulled through the left looped end 18b of theband 16 untilthe abutment surface 300 of the 32 when the set screw 35 istightened as by an allen wrench. Since the band ends 18a and 18b arespaced from one another without any intervening structural element, theyare capable of moving toward one another whatever distance is requiredto cause the band 16 to brakingly engage the drum 15. Preferably, whenthe brake is deactivated, the ends 18a and 18b are spaced from oneanother a distance less than the diameter of the drum 15, and thethickness of the friction material 17 is selected to cause the steelback 18 of the band 16 to engage the drum before the ends 18a and 18bengage one another. As a result, some braking action is always providedregardless of the amount of friction material remaining on the band 16.

The brake assembly 10 possesses other advantages. For instance, in theevent that the band 16 should tend to wear unevenly, it may be readilyreversed. Moreover, should it become desirable for the travel of thelever 13 to be adjusted to compensate for wear, such adjustment may bereadily effected by loosening the set screw 35, pulling the cableelement 31 through its mounting pin 32 and retightening the screw 35.Since 7 many existing vehicles have single-acting braking systems withbrake bands and sheathed cablesof the type illustrated, it should beapparent that such systems may be readily converted into a double-actingsystem simply by installing the mounting bracket 19 in place of themounting mechanism of the single-acting system.

In using the mounting bracket 19, the looped ends 18a and 18b of theband 16 are inserted upwardly through the aperture 29 of the reactionflange 24, and the ends 18a and 18b are engaged at their outer concavefaces against the end edges 21a and 21b of the aperture 29. The loopedends lie between and are located axially by the side edges 26a and 26bof the aperture 29. The cable assembly 14 is connected to the loops, andthe band 16 is located about the drum 15, in the relationship shown inFIGS. 1 and 2.

v In operation, displacement of the lever '13 toward the handle bar 1 1causes the cable element 31 to telescope into the sheath 30, therebydrawing the looped ends together. If the drum 15 is rotating in theclockwise direction as indicated in FIG; 4, the right or leading end 18aengages its reaction surface 21a and the band 16 wraps onto the drum 15causing the left or trailing end 18b to move closer to the right end18a. When the drum 15 is rotating in the counter-clockwise direction asindicated in FIG. 5, the slack in the cable assembly 14 permits the freeend 14b of the cable assembly to move leftward as pressure is applied tothe right looped end 18a through the sheath 30, and the band again wrapsonto the drum 15. When pressure on the lever 13 is relieved, the steelback 18 of the band 16 acts through the cable assembly 14 to displacethe lever 13 away from the handle bar 11 and returns the band 16 to itsinactive position with the ends 18a and 18b engaged with the reactionsurfaces 210 and 21b and the band 16 spaced from the drum 15.

If desired, modified forms of brackets may be provided for use in thebrake assembly of the present invention. For example, as illustrated inFIGS. 6 and 7, a modified brake assembly 110 has a bracket 119 pro videdby a U-bolt having legs 121a and 121b which are bolted to a frame member123. The legs 121a and 121b provide reaction or limit surfaces forengaging the looped ends 118a and 118b of the brake band 116. A bar 127connecting the legs 121a and l2lb and a side plate 126a cooperate toprovide guide surfaces for permitting the band 116 to align itself withits drum 115. A sheathed cable assembly 114 is connected to the band 116in a manner similar to the embodiment of FIGS. land operates similarlyto activate and deactivate the brake assembly 110.

Another embodiment of the present invention is illustrated in FIGS. 8and 9. As seen therein, a brake assembly 210 has a bracket 219 whichincludes a pair of bolts 221a and 221b extending in spaced relation awayfrom a frame member 223 to provide reaction surfaces for engaging theends 218a and 2l8b of a brake band 216. The outer ends of the bolts 221aand 221b are connected together by means of a wire form 227 and theinner ends carry a side plate 226a. The wire form 227 and side plate226a provide guide surfaces for aligning the brake band- 216 with thedrum 215. A flexible sheathed cable actuator 214 similar to theactuators 14 and 114 is provided. Operation of this brake assembly issimilar to the aforedescribed assemblies.

invention. In this embodiment, a relatively wide frame member 323 isdisposed alongside a brake drum 315, and a bracket 319 is provided toshroud the drum 3 15. The bracket 319 has a cylindrical portion 319awhich surrounds the periphery of the brake band 316 and a planar portion31917 which is disposed parallel to the frame member 323.-Thecylindrical portion 319a is provided with an aperture 329 defined by apair of spaced edges 321a and 321b which operate to engage the ends 318aand 318b, respectively of the band 316 when the brake 310 is actuated bymeans of a sheathed actuator cable 314 as described heretofore. Acircular mounting flange 325 extends at a right angle away from thecylindrical portion 319a of the bracket 319 for mounting to the framemember 323 as by screws 350, 350. It is noted that, in this embodiment,the cable assembly 314 is disposed vertically, and a compression spring351 is provided between the ends 318a and 318b of the brake band 316,and surrounds the inner cable 331 of the cable assembly 314. With thisstructure, the brake assembly 310 is protected from foreign matter suchas dirt, water and the like. Moreover, the spring 351 operates toprovide a positive biasing action to en- In FIGS. 10,.and11 there isillustrated yet another modified brake assembly 310 embodying thepresent sure separation of the brake band 316 from the brake drum 315when the brake is deactivated.

The embodiments of FIGS. 1-5, FIGS. 6 and 7, FIGS. 8 and 9, and FIGS. 10and l 1 all employ a common actuator mechanism and operate basically onthe same principle. All of them provide a double-acting brake havingself-aligning and self-locking features. Moreover, all are compact andrelatively inexpensive to manufacture.

If desired, a braking system 410 (FIGS. 12 and 13) may be provided byutilizing a bracket 419 similar to the bracket 19 of the embodiment ofFIGS. l-5. The brake assembly 410 is generally similar to the assembly10 illustrated in FIGS. 1-5; however, in the assembly 410, the actuatingmechanism includes a rigid rod 431 which is fastened at one end to a pin432 carried in the left looped end 418b of a brake band 416. The rod 431is slidably received by another pin 433 carried in the right looped end418a of the band 416. It is noted that in this embodiment, the rod .431is unsheathed. Thus, when the drum 415 is rotating in the clockwisedirection and the rod 431 is displaced axially in the rightwarddirection, the right band-end 418a engages a reaction surface 42la onthe bracket 419 and the band 416 wraps onto the drum 415 to brake thesame. However, when the drum 415 is rotating in the opposite direction,the band 416 may not have the same selfenergizing action as the othermodifications and the braking action may not be of the same magnitude aswhen the drum 415 is rotating clockwise. It is noted that the guidesurfaces 426a and 426b permit the band 416 to align itself with the drum415 as in the brake assembly 10 of FIGS. 1-5.

In view of the foregoing, it should be apparent that an improveddouble-acting brake assembly has now been provided. The brake assemblyis of simple but durable construction and is compact, permitting usagein environments in which there are severe spatial limitations. Thepresent invention provides a low-cost mounting bracket which is capableof being used to convert existing single-acting braking systems intodouble-acting systems and which is also capable of use with arod-actuated braking system.

While preferred embodiments of the present invention have been describedin detail, various modifications, alterations and changes may be madewithout departing from the spirit and scope of the present invention asdefined in the appended claims.

I claim:

1. For use in a brake assembly including a drum rotatable on an axis, aband disposed around the periphery of said drum, said band having endswith portions spaced from one another and extending away from saidperiphery, and actuator means for displacing said ends in a direction tocause said band to engage said drum, including an elongated elementslidably received by one end and secured to the other, a mountingbracket for reacting with said ends to limit rotation of said band inopposite directions about said axis when engaged with said drum, saidbracket having a reaction flange with an aperture having edges defininga pair of reaction surfaces spaced apart a distance greater than thecorresponding spacing of said end portions for loosely receiving saidend portions therebetween and defining a pair of guide surfacesextending between said reaction surfaces for engaging laterally of saidend portions to limit movement of said band axially of said drum, saidbracket also having a mounting flange extending along one side thereofat an angle away from said reaction flange for securement adjacent saiddrum, and including clamping means carried by said other band end anddisplaceable transversely to said element for releasably connecting saidelement to'said other band end to afford longitudinal adjustment of saidelement, said clamping means being exposed opposite said mounting flangeso as to be operable from the side of the reaction flange opposite themounting flange.

2. Apparatus according to claim 1 wherein said mounting flange isintegral with said reaction flange and extends outwardly of said axisbeyond said end portions of said band.

3. In a brake assembly including a brake drum, a band operativelyassociated with said drum and having ends disposed in spaced relation,and actuator means for displacing said ends in a direction to cause saidband to engage said drum, including a cable element connected to one ofsaid ends, a sheath telescopically receiving said cable element andhaving a movable abutment surface confronting the other of said ends,and means providing a slidable connection between said cable and saidother end to slidably receive said cable element, the improvementcomprising: bracket means having a reaction flange providing a pair ofreaction surfaces extending widthwise of said band and spaced apart toreceive said band-ends therebetween,

said reaction flange also having a pair of guide surfaces extendinglaterally of said band-ends between said reaction surfaces, eachreaction surface being coextensive with the widthwide dimension of itsassociated band-end, and said reaction and guide surfaces looselyembracing said band-ends, said bracket means further having a mountingflange extending away from said reaction flange for securing the bracketmeans adjacent said drum periphery, so that when said cable element istelescoped into said sheath, said ends are drawn together and said,cable and sheath move freely therewith for causing the band to engagethe drum.

4. Apparatus according to claim 3 including means carried by said oneend of said band for mounting said cable element to pivot relative tosaid band and means 6. Apparatus according to claim 5 wherein said pincarried by the loop on said one end has a transverse bore for receivingsaid cable element, and clamping means displaceable axially of said pinfor securing said cable element in said pin.

7. Apparatus according to claim 6 wherein said clamping means includes athreaded bore extending axially in said pin and a threaded fastenermounted in said axial bore.

8. Apparatus according to claim 3 wherein said bracket means includes acover portion surrounding the periphery of said band and extending in aplane transverse to the rotational axis of the drum for enclosingsubstantially the entire periphery of the band and the drum.

9. Apparatus according to claim 3 including elastic means normallyurging said ends into engagement with said reaction surfaces to spacesaid band from said drum.

10. Apparatus according to claim 9 wherein said elastic means includes acompression spring engaging between said band-ends and surrounding saidcable element.

11. In a vehicle having a frame element, a shaft mounted to rotaterelative to the frame element, a drum fixedly mounted to the shaft, abrake band surrounding said drum and having ends disposed in spacedrelation adjacent said frame element, the improvement comprising: boltmeans extending away from said frame element and providing a pair ofreaction surfaces extending widthwise of said band-ends in spacedrelation for engaging said ends loosely therebetween to limit rotationalof said band relative to said drum, guide surface means carried on saidbolt means a spaced distance from said frame and extending laterally ofsaid band-ends for positioning said band axially relative to said drum,and actuator means for urging said ends toward one another including aflexible sheath having one end fixedly connected to said frame andanother end engageable against one end of said brake band, a flexiblecable within said sheath, said cable having one end connected to anoperator displaceable relative to the frame and having another endconnected to the other end of said brake band, said sheath and cablebeing disposed relative to the frame to permit the unconnected end ofthe sheath to engage its associated end of the brake band and to movetherewith relative to said frame when said operator is energized totelescope said cable into said sheath with said cable and sheath movingfreely relative to said frame substantially tangentially to said drum.

12. Apparatus according to claim 11 wherein said bolt means includes aU-bolt having parallel legs providing said reaction surfaces and nutmeans connecting said legs to said frame element.

13. A mounting bracket for use with a brake assembly including a drumrotatable on an axis, a resilient brake band disposed around theperiphery of said drum and having reversely-turned ends forming loops atthe ends of the band with said loops projecting outwardly from theperiphery of the band, and actuator means engaged with said loops fordrawing the same toward each other to cause the band to engage the drumin braking relation therewith, said mounting bracket having a reactionflange with an aperture providing a pair of reaction surfaces extendingwidthwise of the band and providing a pair of guide surfaces extendingbetween said reaction surfaces, said reaction surfaces being spacedapart a distance to receive said loops and loosely embrace themtherebetween and to be resiliently engaged by said loops when the bandis in a deactivated condition, said reaction flange being spacedradially from the drum a distance sufficient to receive the ends of theband loosely between the reaction surfaces but less than the maximumoutward projection of the loops,

said actuator means including a sheathed cable connected to the loopsabove said reaction flange and extending alongside said reaction flangeclosely-adjacent thereto in a manner providing free movement of theloops between the reaction surfaces, said bracket also having a mountingflange for securing the reaction flange at said distance, so thatwhenthe band is engaged with the rotating drum the loops move betweenthe reaction surfaces in a direction corresponding to the rotationaldirection of the drum with one loop leading the other and being carriedforwardly in the direction of drum rotation against its associatedreaction surface, whereby the other end of the band wraps onto the drumto provide a self-energizing braking action.

1. For use in a brake assembly including a drum rotatable on an axis, aband disposed around the periphery of said drum, said band having endswith portions spaced from one another and extending away from saidperiphery, and actuator means for displacing said ends in a direction tocause said band to engage said drum, including an elongated elementslidably received by one end and secured to the other, a mountingbracket for reacting with said ends to limit rotation of said band inopposite directions about said axis when engaged with said drum, saidbracket having a reaction flange with an aperture having edges defininga pair of reaction surfaces spaced apart a distance greater than thecorresponding spacing of said end portions for loosely receiving saidend portions therebetween and defining a pair of guide surfacesextending between said reaction surfaces for engaging laterally of saidend portions to limit movement of said band axially of said drum, saidbracket also having a mounting flaNge extending along one side thereofat an angle away from said reaction flange for securement adjacent saiddrum, and including clamping means carried by said other band end anddisplaceable transversely to said element for releasably connecting saidelement to said other band end to afford longitudinal adjustment of saidelement, said clamping means being exposed opposite said mounting flangeso as to be operable from the side of the reaction flange opposite themounting flange.
 2. Apparatus according to claim 1 wherein said mountingflange is integral with said reaction flange and extends outwardly ofsaid axis beyond said end portions of said band.
 3. In a brake assemblyincluding a brake drum, a band operatively associated with said drum andhaving ends disposed in spaced relation, and actuator means fordisplacing said ends in a direction to cause said band to engage saiddrum, including a cable element connected to one of said ends, a sheathtelescopically receiving said cable element and having a movableabutment surface confronting the other of said ends, and means providinga slidable connection between said cable and said other end to slidablyreceive said cable element, the improvement comprising: bracket meanshaving a reaction flange providing a pair of reaction surfaces extendingwidthwise of said band and spaced apart to receive said band-endstherebetween, said reaction flange also having a pair of guide surfacesextending laterally of said band-ends between said reaction surfaces,each reaction surface being coextensive with the widthwide dimension ofits associated band-end, and said reaction and guide surfaces looselyembracing said band-ends, said bracket means further having a mountingflange extending away from said reaction flange for securing the bracketmeans adjacent said drum periphery, so that when said cable element istelescoped into said sheath, said ends are drawn together and said cableand sheath move freely therewith for causing the band to engage thedrum.
 4. Apparatus according to claim 3 including means carried by saidone end of said band for mounting said cable element to pivot relativeto said band and means mounting said slidable connection to pivotrelative to the other end of said band.
 5. Apparatus according to claim4 wherein said ends of said band have reversely turned loops with slotsextending lengthwise of the band, and said cable mounting means includepins rotatably mounted in said loops.
 6. Apparatus according to claim 5wherein said pin carried by the loop on said one end has a transversebore for receiving said cable element, and clamping means displaceableaxially of said pin for securing said cable element in said pin. 7.Apparatus according to claim 6 wherein said clamping means includes athreaded bore extending axially in said pin and a threaded fastenermounted in said axial bore.
 8. Apparatus according to claim 3 whereinsaid bracket means includes a cover portion surrounding the periphery ofsaid band and extending in a plane transverse to the rotational axis ofthe drum for enclosing substantially the entire periphery of the bandand the drum.
 9. Apparatus according to claim 3 including elastic meansnormally urging said ends into engagement with said reaction surfaces tospace said band from said drum.
 10. Apparatus according to claim 9wherein said elastic means includes a compression spring engagingbetween said band-ends and surrounding said cable element.
 11. In avehicle having a frame element, a shaft mounted to rotate relative tothe frame element, a drum fixedly mounted to the shaft, a brake bandsurrounding said drum and having ends disposed in spaced relationadjacent said frame element, the improvement comprising: bolt meansextending away from said frame element and providing a pair of reactionsurfaces extending widthwise of said band-ends in spaced relation forengaging said ends loosely therebetween to limit rotational of said bandrelative to said drum, guidE surface means carried on said bolt means aspaced distance from said frame and extending laterally of saidband-ends for positioning said band axially relative to said drum, andactuator means for urging said ends toward one another including aflexible sheath having one end fixedly connected to said frame andanother end engageable against one end of said brake band, a flexiblecable within said sheath, said cable having one end connected to anoperator displaceable relative to the frame and having another endconnected to the other end of said brake band, said sheath and cablebeing disposed relative to the frame to permit the unconnected end ofthe sheath to engage its associated end of the brake band and to movetherewith relative to said frame when said operator is energized totelescope said cable into said sheath with said cable and sheath movingfreely relative to said frame substantially tangentially to said drum.12. Apparatus according to claim 11 wherein said bolt means includes aU-bolt having parallel legs providing said reaction surfaces and nutmeans connecting said legs to said frame element.
 13. A mounting bracketfor use with a brake assembly including a drum rotatable on an axis, aresilient brake band disposed around the periphery of said drum andhaving reversely-turned ends forming loops at the ends of the band withsaid loops projecting outwardly from the periphery of the band, andactuator means engaged with said loops for drawing the same toward eachother to cause the band to engage the drum in braking relationtherewith, said mounting bracket having a reaction flange with anaperture providing a pair of reaction surfaces extending widthwise ofthe band and providing a pair of guide surfaces extending between saidreaction surfaces, said reaction surfaces being spaced apart a distanceto receive said loops and loosely embrace them therebetween and to beresiliently engaged by said loops when the band is in a deactivatedcondition, said reaction flange being spaced radially from the drum adistance sufficient to receive the ends of the band loosely between thereaction surfaces but less than the maximum outward projection of theloops, said actuator means including a sheathed cable connected to theloops above said reaction flange and extending alongside said reactionflange closely-adjacent thereto in a manner providing free movement ofthe loops between the reaction surfaces, said bracket also having amounting flange for securing the reaction flange at said distance, sothat when the band is engaged with the rotating drum the loops movebetween the reaction surfaces in a direction corresponding to therotational direction of the drum with one loop leading the other andbeing carried forwardly in the direction of drum rotation against itsassociated reaction surface, whereby the other end of the band wrapsonto the drum to provide a self-energizing braking action.